To express that something is important in Engpsh, you can use phrases pke:

"It's crucial/vital/critical/essential that..."
"It's important to..."
"It's a priority/top priority to..."

For example:

"It's crucial that we finish this project on time."
"It's important to eat a healthy diet."
"It's a top priority to keep our customers happy."

You can also use the adjective "important" to describe something:

"This decision is important."
"This meeting is important."

In informal situations, you can also use the slang phrase "It's a big deal" to indicate that something is important. For example:

"I have a big exam tomorrow, so I need to study a lot."
"I'm really excited about my new job – it's a big deal for me."